Hydraulic vibrator for pulp screens



March 5, 1935. w. A. HALIBURTON 1,993,603

HYDRAULIC VIBRATOR FOR PULP SCREENS Filed June 50, 1935 4 Sheets-Sheet 1 lNVENT-OR ATTORNEY March 5, 1935. w. A. HALIBURTON HYDRAULIC VIBRATOR FOR PULP SCREENS Filed June 50, 1935 4 Sheets-Sheet 2 W fljfalj/bwrton/ March 5, 1935. w. A. HALIBURTON HYDRAULIC VIBRATOR FOR PULP SCREENS Filed June 30, 1935 4 Sheets-Sheet W fljfal i/burton' ATTORNEY March 1935- w. A. HALIBURTON HYDRAULIC VIBRATOR FOR PULP SCREENS Filed Ju'ne 50, 1953 4 Sheets-Sheet 4 v ATTOR N EY Patented Mar. 5, 1935 UNITEDSTATES PATENT OFFICE "1 HYDRAI ILIC' VIBRATOR FOR PULP SCREENS 'William A. Haliburton, Canton, N. 0. Application June 30, 1933, Serial No. 678,519

' 5 Claims; (Cl. 92-32) This invention relates to means for operating the pulp screens of paper mills and has for its object the provision of an operating mechanism which will efiectually reciprocate or vibrate the gaskets below the several screen plates without the noise which now attends such operation.

The invention seeks to provide a noiseless mechanism which will operate eificiently at all times and which will reduce. the number of working parts so that the cost of production and of maintenance will be minimized.

Other objects will appear in the course of the following description and the invention resides in certain novel features which will be particularly defined in the appended claims.

In the accompanying drawings:

Figure 1 is a view in side elevation, partly broken away and in section, of one form of'an apparatus embodying by invention.

Figure 2 is a transverse section with parts in elevation.-

Figure 3 is a view similar to Figure 1 but showing a modified arrangement.

Figure 4 is a detail section of the lower end of a vibratory piston or lifter.

Figure 5 is a detail section of'a dashpot rod.

Figure 6 is a vertical section through the main controlling valve. 7

Figure 7 is a section on-the line 7-7 of Figure 6.

Figure 8 is a view similar to Figure 7 but showing a different arrangement of ports.

Broadly stated, my invention substitutes a fiuid-operating mechanism for the cam shaft which is now generally employed.

In the accompanying drawings, the numeral 1 designates a screen frame supported in the usual manner upon standards 2 and containing a plurality of screen plates which are of the usual construction. Disposed within the screen frame, below the screen plates, are gaskets 3 which are secured between'and carried by an upper gasket board 4 and a lower bumper board 5. V Secured to and depending from the bumper board is a piston or vertically vibrating rod 6 which is preferably constructed in sections having their meeting ends overlapped and secured by bolts so that they may beeasily separated in the event of a break and also easily assembled when setting up the apparatus. tion of this piston or reciprocating rod is clearly shown in Figure 2.

As shown in Figure 1, a cross arm 7 is secured to the piston or reciprocating rod 6 and extends to each side thereof and in each end of this The construccross arm is engaged the upper end ofa reftractile spring 8, the lower end of which is engaged with a post 9 rising from a supporting base 10 in .which it is firmly secured. The

springs serve to quickly return the piston and- 5.

the gasket carried thereby to its lowest position after it has been elevated. Attached to the cross arm 7, adjacent each spring 8,.is a' dashpot plunger 11, the'lower end of which plays in a dashpot 12 secured upon the-base 10, 1 as shown, the plunger being preferably con-- structed in sections 13 having their meeting ends reversely threaded so as to engage in a coupling sleeve 14, lock nuts 15 being mounted upon the respective sections 13 and turned home against 5 the ends of the sleeve so as to hold it in a set position. This construction permits the dashers to be adjusted or extended to acquire the requisite efficiency in operation, the dashers working in the dashpot in the usual manner tocushion the descending strokes of the parts.

Mounted upon the base 10, between cooperating dashpots; is a cylinder 16 receiving the lower terminal 17 of the cooperating piston, it being noted, upon reference to- Figure 4, that the lower terminal of the piston or reciprocating rod is circular. in cross'se'ction and fits closely within the bore of the cylinder which receives an operating fluid to act upon the terminal when the mechanism is to operate. A packing gland 18 is fitted in the upper end ofv the cyl: inder 16 around the terminal 17 so as to prevent leakage of the operatingfiuid while pera mitting ready reciprocation of the piston. The cylinder is provided with an inlet port 19 communicating with the lower end of its bore and this port is in direct communication with an inlet pipe 20 which is equipped with a cut-ofi or adjusting valve 21, of any preferred detail construction and leads from a main supply pipe 22 which is disposed in'any convenient manner within the workroom so as to convey a supply of fiuid to the inlet pipe. An air vent 23 is provided in the top of the main supply pipe 22 at intervals in the length thereof so that when starting theapparatus any air which may have been trapped in the supply pipe will be vented therefrom, it being understood that when the apparatus is in operation the pipes will be'filled with the operating fluid from the cylinder '16 back'to the main controlling valve.

In Figure 1 I have shown the reciprocating bar or piston coupled to one gasket 'but this particular. arrangement may be varied and in Figure 3 I have shown the operating piston 24- connected to a coupling bar which is in turn connected with the gaskets below six screen plates. This arrangement will permit two oper ating pistons to accomodate the screens which previously required the used of a six cam shaft while in Figure 1 each piston substitutes for one cam. The coupling bar 25 has an upstanding branch 26 at each end and at its center has a branch 27' which extends up into the screen frame and has its end secured directly to a bumper board in the same manner that the rod 6 is attached to a bumper board in the arrangement shown in Figure 1.

The main supply pipe 22 is in communication with the casing 28 of the main controlling valve through a conduit or pipe line 29 which is coupled to the main supply pipe near one end thereof and extends to the casing 28, as clearly shown in Figures 1 and 2. The casing 28 is a cylinder of proper dimensions having a horizontal partition 30 therein spaced upwardly from the lower edge of its wall and this partition is provided with an inlet port 31 and an outletport 32, the inlet port communicating with the end of the pipe 29 through an elbow 33 provided on the wall of the partition, as clearly shown in Figure 6, An exhaust pipe 34 is secured at its upper end in the outlet port 32 so as to carry from the valve the driving fluid which has performed its work. A valve seat 35 rests upon the partition 30, as shown in Figure 6, and is provided with a port 36 registering with the port 31, this valve seat being secured upon the partition by countersunk bolts for screws, indicated at 37, whereby it may be easily removed when truing thereof is necessary. Resting upon the valve seat is a rotary valve disc 38 which is secured to a shaft 39 and is provided with inlet ports 40 and exhaust ports 41, the ports being provided in any desired number and spaced equidistantly around the valve so that the vibrators may be actuated at desired intervals. The speed of rotation of the valve will be determined by the number of ports, the valve rotating more slowly as the number of ports is increased. For practical efficiency it has been found that a valve with four ports rotated at 175 R. P. M. will give the most satisfactory results. The cylinder 28 has a removable cover 42 and upon said cover and on the under side of the partition 30 are'glands 43 and 44, respectively, around the shaft 39 whereby leakage along the shaft is avoided. The upper end of the shaft also has a bearing in a yoke 45 which is provided on the cover and thereby aids in avoiding bending of the shaft. A pipe 46 leads into the cylinder 28 through the top thereof, as shown.

The shaft 39 may be rotated by any convenient mechanism, a gear case 47 being illustrated below the cylinder 28, gearing therein operatively connecting the lower end of the shaft 39 with a driving shaft 48 which may be set in motion from any convenient prime mover.

It is intended that the main supply pipe 22 and its branches be filled with fluid from the vibrator cylinder 16 back to the main controlling valve and the level of the fluid will be just below the valve seat 35. Any thin fluid may be employed and water will generally be used. A pulsating action is imparted to this fluid by the use of any convenient agent which is admitted to the cylinder 28 and controlled by the valve 38. Steam from the boiler of the factory power plant has been found efficient. The steam will enter the valve casing through the pipe 46 and will act upon the water in the pipe 29 and the communicating conduits so as to cause the said water to lift the several pistons 65. As the valve rotates the steam will be set in communication with the exhaust ports and find its way there through. The steam which enters the valve casing 28 will, of course, reach the surface of the water in the elbow 33 and will exert pressure thereon which will be transmitted through the body of water to the several pistons 6 and said pistons will be caused to rise, yet these gaskets will not go against the screen plates, there being a space between the said screen plates and gaskets at all times. As the valve rotates, the port 40 will'b'e cut off and the steam may then pass out through the exhaust port and the pipe 34. The pipe 34 may lead back to the pump feeding water into the boiler so that the water of condensation may be again converted into steam and very little of the steam may be lost. The ports in the valve are so arranged that the exhaust will follow the inflow quickly, but there will be a more pronounced interval between said exhaust and the subsequent inflow. This arrangement will permit the gaskets to remain at the lower limits of their movements for a longer period than in their upper positions so that the suction upon the screens will be continued through a sufficient period to become efficient. The body of water pulsating between the vibrator cylinder 16 and the controlling valve will constitute a flexible or elastic piston which will operate instantly and without any noise so that the operation of the screens will be quiet and be free from the dirt which is attendant upon the use of cam shafts and similar mechanical devices. Moreover, the number of parts is greatly reduced so that the cost of installation and maintenance will be minimized.

Having described the invention, I claim:

1. Vibrating mechanism for pulp screens comprising a reciprocatory piston, a dash pot coacting with the piston and fluid means for actuating said piston.

2. Vibrating mechanism for pulp screens comprising a stationary cylinder, a piston moving in said cylinder and connected with the gaskets of the screens, means for admitting fluid pressure to the cylinder to elevate said piston, a dash pot coacting with the piston'and resilient means resisting the action of said fluid means for lowering the piston.

3. Vibratory mechanism for a pulp screen comprising a stationary cylinder, a piston in the cylinder connected with the screen, a dash pot coacting with said piston, a valve casing, a conduit connecting the valve casing with the cylinder, a valve in said valve casing operable to close and open the conduit, and means for admitting a pressure medium into the valve casing and exhausting it therefrom.

4. Vibratory mechanism for a pulp screen comprising a stationary cylinder, a piston working in the cylinder and connected with the pulp screen, a dash pot coacting with the piston, a valve casing, a conduit extending between the cylinder and the valve casing, an air vent in said conduit, a valve in the valve casing operable to open and close the end of the conduit, and means for admitting a pressure medium to the valve casing and exhausting it therefrom.

5. Vibratory mechanism for a pulp screen comprising a stationary cylinder, a piston working in the cylinder and connected with the screen, a dash pot coact ing with the piston, a valve casing, a conduit connecting the cylinder with the valve casing, a valve seat in the valve casing having a port registering with the end of 5 the conduit and also having an exhaust port, means for admitting a pressure medium to the valve casing and exhausting said medium from the casing, and a valve movable upon the valve seat and arranged to cover and uncover the end of the conduit and also cover and uncover the exhaust.

WILLIAM A. HALIBURTON. 

